Abstract:

Canine babesiosis is a common, highly virulent disease in Southern Africa with even pups and juveniles being
severely affected. This contrasts with bovine babesiosis, for example, where host, parasite and vector co-evolved
and young animals develop immunity after infection without showing clinical signs. Babesia rossi, the main
causative organism of canine babesiosis in sub-Saharan Africa, was first described from a side-striped jackal (Canis
adustus) in Kenya. Although data are meagre, there is evidence that indigenous African canids, such as jackals and
wild dogs (Lycaon pictus), can harbour the parasite without showing untoward effects. Dogs are not indigenous to
Africa. The vast majority of dogs presented at veterinary facilities in South Africa represent recently introduced
European, Asian or American breeds. The contention is that B. rossi is a new challenge to which these dogs have
not adapted. With intensive treatment of clinical cases, natural selection is effectively negated and the status quo
will probably be maintained indefinitely. It is postulated that Babesia vogeli, which frequently results in unapparent
infections or mild manifestations in dogs, represents or is closely related to the ancestral form of the canine
parasite, possibly originating from wolves (Canis lupus).